Moisture extraction



June 4, 1935. H. L. SMITH, JR

MOISTURE EXTRACTION Filed July 17, 1934 2 Sheets-Sheet l I M, Dav-vINVENTOR HIS ATTORNEYS June 4, 193 5.

H. L. SMITH, JR 2,003,397

I MOISTURE EXTRACTION Filed July 17, 1934 .2 Sheets-Sheet 2 7'0EVACUATOA ll: E::

\NVENTOR 24M 0 Mac M: ATTORNEYS Patented June 4, 1935 UNITED STATESPATENT OFFICE MOISTURE ax'mao'non Horace L. Smith, Jr., Richmond, Va.,assignor to Thermal Engineering Corporation, Richmond, Va., acorporation of v t Application July 17, 1934, Serial No. 735,718 3Claims. (01. 3H8) This invention relates to the extraction of of steamin the ejector and the contamination moisture, and more particularlyconcerns imof the ejector condensate by the foreign matter. provedapparatus for withdrawing moisture from Another object of the inventionis the procloth, fabrics or other materials which are pervision ofanimproved type of vacuum chamber 5 meable to air. for use with moistureextracting apparatus of 5 In many manufacturing processes, it isnecesthe type described. sary to extract moisture from air permeable ma-In general, the above and other objects of my terials. Thus in thefinishing of textiles, a web invention are carried out by providingmoisture of textile fabric is subjected to one or more water extractionapparatus inclu n a v m mrinsing operations prior to sizing or othertreatber into which the air and entrained water are 10 ment, and it isessential that the moisture abdrawn from the fabric or other moistpermeable sorbed by the fabric during rinsing be removed material undertreatment, and by providing therefrom before the sizing or othertreating mans for c n inu ly re v from this terial is applied. It hasbeen customary to exchamber the extracted water and the fore l5 tractthis moisture by continuously passing the matter carried thereby WithoutPassing this wet material over a slot or similar opening in a waterthrough t e exhausting D p other chamber in which a vacuum is maintainedby vacuum producing means. pumps or equivalent means, whereby the mois-In a preferred form of my invention, this is ture in the fabric isentrained and withdrawn by accomplished by connecting the pump or otherthe air drawn therethrough into the vacuum vacuum produ means to a pointabove the 20 chamber. This water withdrawn from the fabbottom of thevacuum chamber and by Providing ric contains a large amount of lint,threads, dye an extracted water outlet means comp in a and other foreignmaterial which is withdrawn downwardly extending duct of considerablelength from the vacuum chamber by the vacuum pump. connected at its uppend to a point at This foreign matter collects on the pump screensjacent the bottom of the vacuum ch m r an 25 and stops the pumpingaction or, if no screens having an air seal or trap at its lower end.with are used, clogs and injures the pumps and causes this arrange theWaller other q d frequent shut-downs or breakage of apparatus. tractedfrom the material under treatment, to-

It has been proposed to overcome the above exg t c w t foreign mattercarried e y.

plained difficulty by using steam jet ejectors for continuously flowsoff by gravity through the 30 maintaining a vacuum within the vacuummoisoutlet duct, and the water seal provided by this ture extractingchamber. Although the use of water at the lower end of this ductprevents the such-ejectors avoids clogging difficulties to a ceregressof air through the duct to the vacuum tain extent, it is unsatisfactoryin other respects. chamber. The pump or other means for main- Thus alarge amount of steam is required to optaining a vacuum in the chamberwithdraws the 35 erate a steam ejector even under ordinary opentrainingair only from this chamber and accrating conditions, and the fiow ofextracted cordingly, the invention entirely prevents the conwater intothe ejector condenses some of .the densation of steam and contaminationof consteam therein before it has performed its ejecdensate in anejector type of exhauster, as well tion function, thereby greatlyincreasing the as the clogging of a pump exhauster. 40 steam consumptionof the ejector. Further, since In a modified form of the invention, thevacuum the water passing through the ejector is contamchamber isprovided with a combined water and inated with lint, dye and otherforeign matter air outlet opening so shaped as to aid in sepaextractedfrom the fabric, the hot water conrating the extracted moisture from theentraining densed from the ejector exhaust is unfit for most air asthese fluids leave the chamber. In a fur- 45 uses and is accordinglywasted. ther modification of the invention, the moisture With the aboveand other considerations in extracting or inlet opening of the vacuumchammind, it is proposed in accordance with the presber is so arrangedas to prevent the distortion of ent invention to provide improvedapparatus for this inlet by the vacuum maintained within the extractingmoisture from air permeable materials chamber. 50 such as cloth or otherfabric, which apparatus, The invention will be best understood byreferwhile. effectively removing the moisture, entirely ence to theaccompanying drawings, in which ceravoids the clogging. of screens orpumps by fortain embodiments thereof have been disclosed; eign matter inthe extracted moisture, the low- In the drawings;

ering of ejector efficiency by the condensation Figure 1 is adiagrammatic representation of a 55 fabric treatment to which themoisture extraction apparatus of the present invention is applicable;

Figure 2 is an elevation, partly in section, of the moisture extractionapparatus embodying the invention;

Figure 3 is a plan view, partly in section, of the apparatus shown inFigure 2;

Figure 4 is a plan view, similar to Figure 3, showing a modified form ofapparatus embodying the invention;

Figure 5 is a sectional elevation of a modified form of moistureextracting apparatus embodying the invention, the section being takenalong the line 5-5 of Figure 6; and

Figure 6 is a plan view of the apparatus shown in Figure 5 disclosing myimproved vacuum chamber inlet slot construction.

The moisture extraction apparatus of the invention may be used whereverit is desired to withdraw moisture from air permeable material. Oneimportant application of this apparatus is in the finishing of woventextile materials. It is customary to thoroughly rinse certain textilefabrics with water prior to the application of starch or sizing theretoor other treatment thereof, and it is usually essential that the rinsewater be removed before the fabric is subjected to further treatment. Inone fabric treating process as illustrated in Figure 1, a continuous Web5 of textile fabric is moved between rinse water sprays 6 whichthoroughly saturate the fabric, after which the web passes over a guideroll 1 and over a. stationary moisture extracting cylinder or vacuumchamber 8. The chamber 8 is provided with a very narrow slot 9 along theupper cylindrical surface thereof, this slot being substantiallycoextensive with the width of the fabric web, as shown in Figures 2, 3and 4. A vacuum is maintained within the chamber 8 by means hereinafterdescribed, and air is accordingly drawn through the fabric as it passesover the slot 9 with the result that the water carried by the fabric isentrained in the air and drawn out of the fabric into the chamber 8. Thefabric web 5 then passes through a sizing bath l0 under a suitable rollI I and'is delivered to drying or other treatment means, not shown, overthe guide roll l2.

The apparatus of the present invention acts to maintain the desiredvacuum in the chamber 8 by continuously removing the entraining air andthe extracted water from this chamber. The vacuum creating means maycomprise a vacuum pump, a steam ejector or any other device capable ofcontinuously withdrawing air from the chamber 8 at a suitably high rateof flow.- In the embodiment of the invention shown in Figure 2, a steamjet ejector, generally designated J, is employed for maintaining avacuum in the chamber 8. This form of evacuating means is particularlyadaptable in many textile finishing plants where heated wateris'employed in various treating processes, since the hot water recoveredfrom the ejector may be usefully employed in such plants.

The ejector J may be of known construction and as shown comprises asteam nozzle l3 located in a chamber l 4 and disposed to direct a highvelocity steam jet axially through a contracted throat or Venturi tubel5. In accordance with the invention, the suction pipe l6 of the ejectoris connected to the vacuum chamber 8 at or adjacent the top thereof, andas shown in Figure 2. this pipe is connected to the upper surface of thechamber 8 adjacent one end of the chamber and communicates with thechamber ll of the ejector adjacent the nozzle l3. Steam is supplied tothe ejector nozzle l3 from a suitable source through the pipe l1.

The outlet or exhaust pipe 18' of the ejector J is connected to suitablecondensing means illustrated at C. The condenser may take any suitableform and as shown comprises a chamber [9 communicating with the ejectorexhaust pipe l8 through an inlet opening 20 at its upper surfaceadjacent one end thereof, and a condensate outlet 2| in its lowersurface adjacent its opposite end. Cooling water is sprayed into theinlet end of the chamber l9 through a pipe 22 and small auxiliary watersprays 23 are provided at spaced points along the center of the chamber.An air outlet opening 24 is provided at the outlet end of the condenserchamber as shown. In operation, the

air and steam delivered by the ejector exhaust l8 passes through thecondenser chamber IS, the steam is condensed by the water sprays and themixed condensate and spray water flow off through the outlet 2 I, theair passing out through the opening 24.

By properly designing the condenser, the water recovered therefrom maybedelivered at a comparatively high temperature and usefully employed invarious processes such as those incident to the finishing andmanufacture of fabrics.

As explained above, the water extracted from the fabric web 5 iscontaminated with lint, threads, dye and other foreign matter. If thiscontaminated water passed through the ejector J, the hot water recoveredfrom the ejector exhaust would be unfit for use in most manufacturingoperations. Further, if the comparatively cold water extracted from thefabric passed into the ejector chamber H, it would come into directcontact with and condense some of the steam in the jet from the nozzlel3 before this steam could perform its propelling function in the throatHi. In accordance with the present invention, the water extracted fromthe fabric is separated from the entraining air in the vacuum chamber 8and is continuously removed from this chamber without passing throughthe exhausting mechanism and without either breaking the vacuum in thechamber or employing pumps or equivalent propelling means.

In order to remove the contaminated extracted water, I provide a liquidcolumn in a vertically extending duct 25 connected at its upper end to apoint adjacent the bottom of the vacuum chamber 8, and having a liquidseal or trap at its lower end. The liquid seal or trap may comprise areverse bend at the lower end of the duct 25 the upwardly extending legof the duct being shorter than the downwardly extending leg thereof asshown. The outlet of the duct may be connected to a sewer or other wastewater receiver.

In the.operation of the apparatus described. the water saturated fabricweb 5 passes over the slot 9 in the vacuum chamber 8 and the vacuumcreated within the chamber 8 by the ejector J causes air to flow at ahigh velocity through a limited area of the fabric thereby entrainingand extracting water therefrom. The slot 9 is very narrow. in practiceit may be from .005 to .064 inches wide. Accordingly, although thevelocity of the air and entrained water through the slot it- 'self isvery high, this velocity immediately drops to a much lower value as'theair and water enter the chamber 8. At this point, the extracted waterfalls to the bottom of the chamber 8 and flows off by gravity to theduct while the entraining air is drawn off through the ejectorasexplained above. The duct 25 is so designed as to vertical extent andcross section that the water column built up therein by the vacuum inthe chamber 8 is capable of balancing the highest vacuum which theejector apparatus can establish in the vacuum chamber. Thus the wateroutlet duct is always sealed, and at the same time permits thecontinuous flow of extracted contaminated water from the chamber 8.

As explained above, pumps or other mechanica exhausting means may beused on my improved moisture extracting apparatus. This embodiment isdisclosed in Figure 4 wherein an exhaust or vacuum pump, conventionallyrepresented at P, is connected through a duct I6 with the upper surfaceof the vacuum chamber 8'. The chamber 8' is provided with a trappedwater column outlet duct 25' which may be identical with the duct 25 ofFigure 2. With this arrangement, the contaminated water separates bygravity from the entraining air in the vacuum chamber 8' and flows offthrough the duct 25', and the clogging or injury of the pump-P by thelint and other foreign matter in the extracted water is effectivelyavoided.

In a modified form of the invention, as shown in Figure 5, the vacuumchamber 21 is provided with a single outlet 28 at one end thereofthrough which both the entraining air and the extracted moisture pass,and which is so shaped as to aid in separating the moisture from the airat this point. Thus the outlet end of the vacuum chamber 21 communicatesdirectly with the downwardly extending water outlet pipe or duct 29 andthe upper surface of the chamber outlet duct 28 is curved downwardly asshown at 30 toward the upper end of the pipe 29. Just beyond thisdownward curve, the duct 3| leading to the evacuator is joined to thevacuum chamber outlet duct 28 and the water outlet 29, the arrangementbeing such that in entering the air duct 3|, the airmakes a U-bend andsubstantially reverses its direction of fiow'. With this arrangement, asthe stream of air and water flows out of the vacuum chamber. 21 throughthe duct 28, this stream is deflected downwardly toward the water outletpipe 29 and the water in the mixture, being considerably heavier thanthe air, continues to flow downwardly into the pipe 29 while the lighterair passes upwardly around an acute angle bend into the air duct 3i tothe evacuator. It is, of course, to be understood that a steam jetejector, vacuum pump or other type of evacuator is connected to the airduct 3!.

A modified form of water seal for the water outlet duct is disclosed inconnection with the apparatus shown in Figure .5. This seal comprises alarge tank or other receptacle 32 in wh ch the lower end of the pipe 29is submerged. The ca- I pacity of the tank 32 is such that when it isfilled to the level of its overflow pipe 33 and the evacuator isstarted, the column of 'water drawn up in the pipe 29 will not empty thetank 32 to a point where the lower end of the pipe 29 is uncovered. Inother words, the tank 32 has a greater volumetric capacity than the pipe29 or at least a greater capacity than that portion of the pipe 29 whichis filled with water when the evacuator is in operation. With thisarrangement, when the moisture extracting apparatus is started up afteran idle period, the water seal in the pipe 29 is not broken and therequired vacuum is quickly built up in the chamber 21 regardless of therate of flow of extracted liquid into the upper end of the pipe 29. aThe water seal disclosed in Figure 5 is, of course, applicable to allmodifications of my improved moisture extracting apparatus.

Another featm'e which is applicable to all forms of apparatus embodyingmy invention is an improved inlet opening for the vacuum chamber whichis illustrated in Figure 6. In order that the entraining air shall passthrough the web 5 at a very high velocity and thus extract substantiallyall of the moisture therefrom, it is desirable that the slot beextremely narrow and that a high degree of vacuum be maintained in thechamber 21. With the apparatus designed to handle a web 5 ofconsiderable width, there is some danger that the vacuum-chamber maycollapse due to the vacuum therein to such an extent that the inlet slotor portions thereof are contracted or closed, thus interfering with themoisture extracting operation. It is difficult and expensive to brace orreinforce a continuous slot without placing obstructions in the path ofthe air and entrained water drawn therethrough. In accordance with onefeature of my invention, I overcome the above noted difliculties byforming a plurality of comparatively short slots 34 in the surface ofthe vacuum chamber 21, these slots being disposed with their ends inoverlapping relationship, as shown in Figure 6, and being closely spacedso that the web 5 extends over all of these slots. I prefer to arrangethe slots 34 as shown in substantially parallel relationship and at aslight angle to the axis of the vacuum chamber. With this arrangement, abridge of metal, indicated at 35, extends between the ends of theadjacent slots and prevents the closing of the slots due to the collapseof the vacuum chamber. The individual slots may be of any desired lengthshort of that at which there is danger of restriction or closing thereofand any desired width of web may be handled by increasing the number ofoverlapping slots employed. Since the ends of the adjacent slots 34overlap transversely of the web, moisture is extracted fromthe webacross its entire width.

Although the invention has been described in connection with certainforms of apparatus employed in the extraction of water from textilefabrics, it should be understood that the invention is generallyapplicable to any operation in which water or moisture are extracted bythe suction of air through the material under treatment, and thatvarious changes and omissions may be made in the apparatus used withoutdeparting from the scope of the invention as defined in the appendedclaims.

jacent its upper surface, means for condensing steam from said ejectorand a downwardly extending water outlet duct having its upper end incommunication with said chamber adjacent the lower surface of saidchamber and having a reverse bend adjacent its lower end.

2. Apparatus for extracting moisture from permeable material comprisinga vacuum chamber having a restricted inlet opening therein, means forcontinuously moving moist air permeable material over said opening, asteamjet ejector having an inlet duct connected to said chamber adjacentits upper surface, means for condensing steam from said ejector, adownwardly extending water outlet duct having its upper end incommunication with said chamber adjacent the lower surface of saidchamber, and a water seal at the lower end of said duct.

3. Apparatus for extracting moisture from permeable material comprisinga vacuum chamber having a restricted inlet opening therein, means forcontinuously moving moist air permeable material over said opening, asteam jet ejector having an inlet duct connected to said chamberadjacent its upper surface, means for condensing steam from saidejector, a downwardly extending water outlet duct having its upper endin communication with said chamber adjacent the lower surface of saidchamber and a receptacle surrounding the lower end of said duct andhaving a volume above the lower end of said duct at least equal to thevolume of liquid carried by said duct.

' HORACE L. SMITH, JR.

